P1695: REAL-WORLD SURVIVAL, HEALTHCARE RESOURCE UTILIZATION, AND COSTS AMONG U.S. ELDERLY PATIENTS WITH DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL) TREATED WITH R-GEMOX IN THE RELAPSED/REFRACTORY SETTING
Authors: Mahek Garg, Justin Puckett, Sachin Kamal-Bahl, Monika Raut, Katherine Ryland, Samhita Chakraborty, Jalpa Doshi, Scott Huntington
Journal: HemaSphere (2023)

Topic: 36. Ethics and health economics Background: Many patients with relapsed/refractory (R/R) DLBCL are ineligible for intensive treatment such as stem-cell transplant due to age or comorbidities. Globally, the combination of rituximab, gemcitabine, and oxaliplatin (R-GemOx) is one of the most widely used therapies among transplant ineligible patients with R/R DLBCL. However, little recent real-world evidence exists on this treatment regimen, particularly in older adults. Aims: To characterize survival, healthcare resource use (HRU), and costs in elderly U.S. patients with DLBCL treated with R-GemOx in the R/R setting. Methods: Using 2014-2019 medical and prescription claims from the U.S. Medicare database, we identified individuals aged ≥66 years with a DLBCL diagnosis between 10/01/2015 and 12/31/2018 (index date = first DLBCL diagnosis date) and continuous fee-for-service Medicare coverage in the 12 months pre-index and a minimum of 12 months post-index. A claims-based algorithm developed from prior published approaches was used to identify lines of therapy. Our final study cohort included patients with evidence of R-GemOx treatment in the second-line (2L) or third-line (3L) setting. Outcomes included overall survival, all-cause and DLBCL-related HRU and costs after R-GemOx initiation. Results: The final sample included 157 patients who received treatment with R-GemOx in the R/R setting (mean age 77.5, 39.5% age>80 years; 66.9% male; 91.1% White). Of these, 126 received R-GemOx in the 2L setting and 31 received R-GemOx in the 3L setting. Among patients who received R-GemOx in the 2L setting, they primarily received a CHOP-based (68.3%) or bendamustine-based (13.5%) regimen in the 1L setting. Over a median follow-up of 8.4 months from initiation of R-GemOx in the 2L setting, 29.4% of these patients progressed to 3L therapy, most commonly another traditional chemotherapy regimen (54.1%). Among these patients, the mean time from end of R-GemOx treatment to start of next treatment was 2.9 months. Median overall survival from R-GemOx initiation was 6.9 months and 6.8 months in the 2L and 3L setting, respectively; the 1-year survival rate was 38.2% (2L) and 37.0% (3L) from R-GemOx initiation. In the 2L setting, 68.1% of patients had evidence of an all-cause hospitalization and 42.9% had evidence of hospice use within 12 months of R-GemOx initiation. In the 3L setting, over 90% of patients had evidence of an all-cause hospitalization and over half (51.7%) had evidence of hospice use. All-cause total costs were $144,653 within 12 months of R-GemOx initiation in the 2L setting; 79% of costs were DLBCL-related. DLBCL-related medical costs ($80,289) were responsible for 70% of DLBCL-total costs and were more than double DLBCL-related drug costs ($34,252). Similar patterns of high all-cause ($142,812) and DLBCL-related ($86,441) total costs were observed within 12 months of R-GemOx initiation in the 3L setting. Summary/Conclusion: This real-world study of elderly U.S. Medicare beneficiaries found short treatment free intervals, poor overall survival, high rates of healthcare resource utilization, and substantial costs among patients initiating R-GemOx treatment for R/R DLBCL. Our study results suggest large unmet need and underscore the importance of newer, more efficacious agents with manageable tolerability profiles that can be used in combination or as an alternative to R-GemOx for elderly patients with R/R DLBCL. Keywords: Cost analysis, Elderly, Survival, DLBCL